This project will result in a quantitative physico-chemical characterization of the requirements for the transport of 7-substituted- 4-hydroxyquinoline-3-carboxylic acids into Ehrlich ascites tumor cells. These molecules which are inhibitors of respiratory enzymes will be tested for their ability to inhibit the respiration of the ascites cells as compared to their ability to inhibit malic dehydrogenase and these results analyzed by computerized multiparameter regression analysis. A comparative analysis of the physico-chemical features of the proposed molecules which are required for transport when combined with the features responsible for enzyme inhibition will lead to the design, synthesis, and testing of molecules which should be potent enzyme inhibitors capable of selective transport into cancer cells vs. normal cells.